Ozone is a highly reactive substance which naturally occurs as a gas comprised of three bonded oxygen atoms. Common uses of ozone include the treatment of drinking and swimming pool water, the treatment of industrial waste, the bleaching of inorganic products such as clay, and as a disinfectant. Ozone is formed by breaking apart diatomic oxygen molecules, with the free oxygen atoms thus produced reacting with conventional diatomic oxygen molecules to form ozone. In the past, two methods have been used to produce ozone for commercial purposes. These two methods involve ultraviolet (UV) radiation and corona discharge. Ultraviolet ozone generation has been used primarily in air ducts and for the preservation of food and is a relatively inefficient source of ozone.
Corona discharge is on the order of 2½ times as efficient as ultraviolet light in terms of energy required to produce a corresponding amount of ozone and has been used to provide greater quantities and higher concentrations of ozone than UV light. Ozone is produced by corona discharge by positioning two parallel metal plate electrodes in relatively closely spaced relation and passing a high voltage alternating current through the two electrodes. Electrons traveling between the two electrodes collide with oxygen in the atmosphere to break apart the diatomic oxygen molecules, with the thus freed individual oxygen molecules reacting with the diatomic oxygen molecules to produce ozone. Although more energy efficient than the UV radiation approach to producing ozone, the corona discharge approach is also a relatively inefficient source of ozone and requires extensive safety provisions and complex installations because of the high voltages involved in this approach for ozone production.
Ozone has been used in several applications to promote clean air and improve the atmosphere. For example, an ozonizer is disclosed as positioned in an exhaust duct of a vacuum cleaner to purify the exhaust air of the vacuum cleaner in U.S. Pat. No. 5,185,903. One problem that this approach arises from the propensity of ozone to act as a strong irritant causing discomfort to the eyes and throats of those in the vicinity of the ozone source. Higher concentrations of ozone are also believed to affect mental awareness and general health.
Ozone is also disclosed for use in a circulating liquid cleaning solution for cleaning, sanitizing and deodorizing the application area in U.S. Pat. No. 7,302,733. However, in this approach, ozone is introduced in a gaseous state, with some of the ozone dissolved in the liquid cleaning solution, while some of the ozone remains in the gaseous state. Thus, this approach directly introduces ozone into the air and requires a carbon filter or an ultraviolet energy source in its exhaust system to limit the ozone concentration of its emissions. In addition, this approach uses the relatively inefficient approach of ultraviolet light generation of ozone which, as discussed above, is much less energy efficient than even the corona discharge approach to ozone generation.
The present invention addresses the problems encountered in the prior art in the generation and use of ozone in mobile cleaning machines to provide a safe and economical approach to purifying the water in a mobile floor cleaning machine.